Task Manager, prettied up over the years, but still essentially the same core code as Dave's original...
From El Reg's piece:
The Microsoft developer who wrote Task Manager, along with other utilities and games, has popped up to "write this stuff down before I forget it all". A post on Reddit goes into detail about the tool, familiar to every Windows expert, which if you are lucky lets you terminate errant applications or processes, as well as providing some handy stats on how your PC is or is not performing. Dave Plummer, or davepl, "started in MS-DOS in 1993 and spent a little more than a decade at Microsoft, leaving after Server 2003", he told the University of Regina. He talked about the challenges of "coding for a billion machines", saying: "It's like you're building one bull to be released into an infinite number of china shops."
Plummer worked on Double Space, which increased available disk-space in MS-DOS. In his spare time, he developed a utility called VisualZIP, which lets you view compressed Zip files like folders, and sold it as shareware before it was picked up by Microsoft for integration into Windows.
It sounds like a relaxed arrangement, and Task Manager had similar origins. "The Windows Task Manager was a shareware app I wrote in my den that I was planning to sell on the side," Plummer said. "But when [Windows NT architect] Dave Cutler saw it, he agreed to let me check it into the product, so I donated that one." The utility first appeared in Windows NT 4.0, released in 1996.
Plummer said: "TM is one of the apps I'm most proud of because it is probably the first or at least most visually complicated app to ever be fully resizable in all dimensions without any flicker... it was under 100K for the exe and never flashed or crashed, that was my thing! Having the GDI32 and User32 guys down the hall sure helped."
He also offered some tips. "If Task Manager ever hangs or crashes, start another by pressing ctrl-shift-esc," he said. This requests a "secret code" from the existing instance, and if not received, starts another one; and this works to launch the utility even "if the Shell/Explorer is dead".
According to Plummer, many users do not appreciate the full capabilities of his utility, which can be used to launch applications without using the Shell (a life-saver in some circumstances). File - Run new task is the option for this. Another widely unknown feature is the ability to display additional columns, letting you dive into different types of working set for memory usage, and see details like I/O reads and writes.
Indeed, Task Manager is the thing I head for immediately when working out why a PC is running slowly. Note that Plummer left Microsoft in 2003 before the release of Windows Vista, so Task Manager today has been prettified and adapted.
Note that a similar set of views is available in Windows 10 Mobile, I'll show how to bring them up later this week.